The present invention generally relates to a combination garment hanger/storage apparatus for use in a factory and more particularly, relates to a combination garment hanger/storage apparatus for hanging worn garments and for storing clean garments and shoes in a gowning room of a semiconductor fabrication facility.
In the recent development of semiconductor fabrication technology, the continuous miniaturization device fabricated demands more astringent requirements in the fabrication environment and contamination control. When the feature size was in the 2 xcexcm range, a cleanliness class of 100xcx9c1,000 (i.e., the number of particles at sizes larger than 0.5 xcexcm per cubic foot, was sufficient. However, when the feature size is reduces 0.25 xcexcm, a cleanliness class of 0.1 becomes necessary.
It has been recognized that an inert minienvironment may be the solution to future fabrication technologies when the device size is further reduced. In order to eliminate micro-contamination and to reduce native oxide growth on silicon surfaces, the wafer processing and the loading/unloading procedures of a process tool must be enclosed in a extremely high cleanliness minienvironment that is constantly flushed with ultrapure nitrogen that has no oxygen or moisture.
Different approaches in modern clean room design have been pursued in recent years in the advent of the ULSI technology. One is the utilization of a tunnel concept in which a corridor separates the process area from the service area in order to achieve a high level of air cleanliness. Under the concept, the majority of equipment maintenance functions are conducted in low-classified service areas, while the wafers are handled and processed in more costly high-classified tunnels. For instance, in a process for 16 M and 64 M DRAM products, the requirements of contamination control in a process environment is so stringent that the control of the enclosure of the process environment for each process tool must be considered. In order to maintain the high cleanliness class required, the loading and unloading of the process tool must handled automatically by an input/output device such as a SMIF apparatus. The clothing of the machine operator must also be stringently cleaned without introducing particle contaminations into the clean room.
The continuous monitoring of particles, temperature and humidity conditions inside a clean room is required for alerting engineers to changes occurring in the clean room environment such that steps may be taken to prevent particle-sensitive fabrication processes from drifting out of control. The proper gowning procedure and clean room maintenance practices are both critical to prevent any possible micro-contamination in the clean room.
It has long been recognized that the human operators are major sources of clean room contaminants. For instance, not only the operators generate a large number of contaminants, but also the operators are in close proximity to the wafers at many different stages of the fabrication process. As a result, a proper gowning procedure becomes critical in minimizing the exposure of human hair, bare skin and contaminants carried on street clothes.
To minimize human contamination, it has been a common practice in IC fabrication facilities to require its clean room operators to change from street clothes and street shoes into company-provided clean room suit, a face mask and booties over the street shoes. These clean room suits, masks and booties are worn on the outside of street clothes of clean room operators in a designated area immediately adjacent to a clean room normally known as a gowning room.
A good clean room suit material is normally made of woven fabrics that consist of long synthetic fibers covered with a layer of low friction polymeric material. The polymeric coating material prevents particles from passing through while at the same time allows vapor transmission. The clean room suits and booties are washed regularly using deionized water and sodium-free detergent. Stringent procedures must be followed in providing laundry services to the suits and booties in order to minimize contamination while washing, packaging, transporting, and storing these clean room garments.
To further minimize contamination by the clean room garments, i.e. suits and booties, the storage of such garments becomes an important consideration in designing a gowning room. Not only must the particle contaminants be minimized and strictly controlled, but the unit space required for storing clean room garments for each operator need also be minimized in order to conserve the gowning room area which is frequently limited due to its close proximity to the clean room. In a conventional garment storage area for a clean room, wooden shelves and hangers have been used which become another major source of contaminating particles. Furthermore, the traditional wooden shelves, or shelves made of other material, occupy an excessive volume of space for each clean room personnel, for instance, a volume of space of 0.14 cubic meter per clean room operator is normally required. As clean room operation becomes larger and more complicated such that the number of clean room personnel required increases accordingly, it becomes more critical to conserve the gowning room area in order to maximize the number of clean room personnel it is able to service. The large space requirement of 0.14 cubic meter per clean room personnel becomes unacceptable in modern large-sized clean rooms.
It is therefore an object of the present invention to provide a garment hanger/storage apparatus for use in a clean room gowning area that does not have the drawbacks or shortcomings of the conventional garment hanger/storage apparatus.
It is another object of the present invention to provide a combination garment hanger/storage apparatus for use in a clean room gowning area that maximizes the number of clean room personnel it services.
It is a further object of the present invention to provide a combination garment hanger/storage apparatus for use in a clean room gowning area that minimizes the introduction of contaminants.
It is another further object of the present invention to provide a combination garment hanger/storage apparatus for use in a clean room gowning area that can be used for hanging worn garments, storing clean garments and boots.
It is yet another object of the present invention to provide a combination garment hanger/storage apparatus for use in a clean room gowning area constructed by two up-standing lockers for storing clean garments and boots connected by a frame thereinbetween for hanging worn garments.
It is still another object of the present invention to provide a combination garment hanger/storage apparatus that utilizes less than 0.1 cubic meter per clean room personnel.
It is yet another further object of the present invention to provide a combination garment hanger/storage apparatus that utilizes only 0.07 cubic meter per clean room personnel.
In accordance with the present invention, a combination garment/storage apparatus for storing clean garments and boots and hanging worn garments in a clean room gowning area is provided.
In the preferred embodiment, a combination garment hanger/storage apparatus is provided which includes a first locker and a second locker arranged in a back-to-back spaced apart relationship having a first distance thereinbetween. The first locker has a first side facing the second locker and a backside sealed by a side panel and a back panel respectively, a second side facing away from the second locker and a front side arranged in a plurality of racks formed by a plurality of shelves for storing garments and shoes. The second locker has a first side facing the first locker and a back side sealed by a side panel and a back panel respectively, and a second side facing away from the first locker and a front side arranged in a plurality of racks formed by a plurality of shelves for storing garments and shoes. An upper frame that has a length of a first distance connecting an upper end of the side panel of the first locker to an upper end of the side panel of the second locker for hanging garments thereon. A lower frame that has a length of a first distance connecting a lower end of the side panel of the first locker to a lower end of the side panel of the second locker for providing structural rigidity to the combination garment hanger/storage apparatus.
In the combination garment hanger/storage apparatus, the plurality of racks further includes racks for garments and racks for shoes. The plurality of racks may further include racks for clean garments and racks for boots. The upper frame may further include a plurality of hook means for hanging garments. The first locker, the second locker and the upper frame may be sufficient for storing and hanging at least 50 worn garments, 50 clean garments and 50 pairs of shoes. The upper frame may further include at least 50 hook means for hanging worn garments. Each of the first and second lockers may have a top panel provided with ventilation apertures. Each of the first and second lockers may be equipped with wheels mounted on a bottom panel for rollingly engaging a floor surface and for rollingly moving the combination garment hanger/storage apparatus. The first locker, the second locker and the upper and lower frames may be fabricated of a material that does not generate contaminating particles or fabricated of stainless steel.
In another preferred embodiment, the present invention provides a garment hanger/storage rack that includes a first up-standing locker that has at least one side sealed by a panel and at least two sides provided with open shelves sufficient to store at least 25 clean garments and at least 25 pairs of boots, a second up-standing locker that has at least one side sealed by a panel and at least two sides provided with open shelves sufficient to store at least 25 clean garments and at least 25 pairs of boots, an upper frame connecting a top portion of one of the at least one sealed panel on the first up-standing locker to a top portion of one of the at least one sealed panel on the second up-standing locker for hanging at least 50 worn garments and a lower frame connecting a bottom portion of one of the at least one sealed panel on the first up-standing locker to a bottom portion of one of the at least one sealed panel on the second up-standing locker for providing structural rigidity of the garment hanger/storage rack. A second frame may further include at least 50 hook means for hanging the at least 50 worn garments. A total volume of space needed for a worn garment, a clean garment and a pair of boots per each personnel is not more than 0.1 m3. Each of the first and second up-standing lockers has a top panel equipped with ventilation apertures. Each of the first and second up-standing lockers is equipped with a bottom panel and at least 4 wheel means mounted on each bottom panel for slidingly engaging a floor surface. Each of the upper frame and the lower frame has a length sufficient for hanging and a cross-sectional area sufficiently rigid for supporting at least 50 garments. The first and second lockers and the upper and lower frames are fabricated of stainless steel.